The effects of commonly prescribed psychotropic drugs such as methylphenidate, pemoline, and dextroamphetamine on the behavior of children from about 5 to 12 years of age who display hyperactivity, impulsivity, and are diagnosed as MBD (minimal brain dysfunction) will be systematically studied. A number of measures will be used to asses drug effects: teacher, parent, and physician rating scales; short-term memory tasks; psychological tests such as intelligence tests and impulsivity tests; cardiovascular measures of heart rate and blood pressure under rest and mild exercise stress; growth in terms of height, weight and body composition; gas chromatographic and mass spectrometry analysis of metabolites in the blood and urine; and psychophysiological monitoring of attention. An anterospective long-term follow-up will be continued on about 100 children who received stimulation medication (some for 5 years), on children whose medication has been discontinued, and on cohort children. Studies of dose-response relationships between mg/kg doses of psychotropic drugs and learning performance, social behavior in classrooms, and psychophysiological measures of attention will be conducted. Surveys of special education classes to obtain information about the prevalence of usage of psychotropic drugs with the retarded, emotionally disturbed, and learning disabled will be continued. BIBLIOGRAPHIC REFERENCE: McNutt, B. A., Ballard, J. E., Boileau, R. A., Sprague, R. L., & von Neumann, A. The effects of long-term stimulant medication on growth and body composition of hyperactive children. Psychopharmacology Bulletin, 1976, 12, No. 2, 13-15.